I am almost certain that the answer is to use the space for airline and flight number and in the Airline space you put the Cruise Line name and where it asks for the Flight Number you put in the name of the ship. .......Neil.
There is no necessity to fill in any details in those boxes as the system will allow you to by pass that section. I'm not travelling until March and I don't have any flight details as yet. My application was authorised without inputting any travel information. Happy cruising......Jan .
What always gets me with this form is the question are you a terrorist YES/NO.
Yes there should be a 'don't know' option!!!
Regarding the Esta form.I know that P&O have a VISA Dept to help with applications [0845 0710307].
So I would imagine that most Cruise Lines have a similar Dept.
You do not need to complete the holiday information as the form is valid for 2 years and your plans may change - you only have to complete the information which has a red asterix next to it - be careful which site you use as there are a lot of dodgy ones that want to charge you. The official site is: https://esta.cbp.dhs.gov/.